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	<title>Document</title>
	<script>
		console.log(parseInt(3.7999)); //3
		console.log(parseInt('379'));//合法的数字字符串开头
		console.log(parseInt('3e7'));//合法的数字字符串开头
		console.log(parseInt('e37'));//非法的数字字符串开头
		console.log(parseFloat(3.7999)); //3
		console.log(parseFloat('379'));//合法的数字字符串开头
		console.log(parseFloat('3e7'));//合法的数字字符串开头
		console.log(parseFloat('e37'));//非法的数字字符串开头
		console.log(isNaN(5));
		console.log(isNaN(NaN));
	</script>
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